Steam Turbine, the Easy DIY Way

Introduction: Steam Turbine, the Easy DIY Way

Heron's steam ball (turbine) made from a tin of condensed milk and some copper pipe.

I designed and built the origional one of these when i was about seven years old and the design hasent changed since. Since it was designed by a seven yr old its simple, debatably free and easy to make.

This is probably the simplest of my creations and all you need to make it is a can of condensed milk and some brake piping you can get free from any local garage.

Swivel or thread that can be twisted ALOT and hold the weight of a can half filled with water.

Tools Required:* Soldering Iron.

Something to make approximately 5mm holes with. Drill or large nail will do.

Hammer if you are using a nail.

Heat source like a trangia, camping stove or blow torch.

Potentially a pair of pliers or a vice.

Pipe bender would be helpful but not required

Sand paper, scouring pad or brush.

Gather all materials needed, you should be able to buy a cheap can of condensed milk for a pittance and hydraulics tubing is usually free from the scrap yard or garag. Hence why I frequently use it. Solder you will have to buy and it isn't cheap but I was lucky because my granddad was an amateur electronics enthusiast and so I borrowed some of his. At a pinch araldite or epoxy resin could be used but it is only temperature resistant to around 120 Degrees Celsius which is 20 above waters boiling point so it should be fine, you can add a volatile liquid like acetone or ethanol to the water to lower the boiling point slightly to about 75 degrees centigrade. Also it is expensive but exhaust pipe adhesive available from car specialist shops is temperature resistant to around 250 degrees Celsius which is more than enough.

Step 2: Make Two Holes and Empty the Can

Take the label of your tin and make two holes roughly 10mm form the top on opposite sides of the can. to find the oposite sides of the can I used a strip of paper which i wrapped around the can, marked the overlap, folded in half and then wrapped it around the can again and marked the marks on the can.

Then, using a larger nail or such, widen the hole to the desired diameter which is slightly less than that of the pipe so the pipe will be a snug push fit. This will leave a lip on the metal where it was stretched and torn inwards which will make it easier for you to attach your tubes effectively. Now you have two holes in your can on opposite sides empty the contents by squirting water in one hole and the milk will come out the other.

Alternatively you could use a drill. In this case use a centre punch or other sharp ended metallic object to make a dent with a hammer 10mm from the top. Using a drill bit slightly smaller than the outer diameter of your pipe drill a hole through the side using the dent to steady the drill on the round surface.

Step 3: Cut and Bend Your Tubes

Cut two lengths of pipe 115mm long using your pipe cutter, a hack saw or the cutters on pliers and bend one end of the pipe at the end by 90 degrees so the last centimetre of the pipe is perpendicular the main length. This can be achieved by putting two pegs in a piece of wood and putting the pipe in between them then carefully bending the pipe around the peg until the pipe is the desired shape, or use a pipe bender, if you're stuck you could just do it free style with your hands but be careful it's easy to crimp the tube.

Clean your joints so that you will have a good surface to join. Use a fine grain sand paper if available or a scouring pad/ brush if not.

Step 4: Attach Your Tubes

Get your adhesive ready or your soldering iron warmed up ready for use and push the long end of your bent tube into one of the holes you have made, make sure the end is pointing anti-clockwise and attach it in place. Repeat for other side.

Step 5: Test It

Now just fill with water preferably from the kettle as hot as possible (BE CAREFULL) and attach a piece of steel cable tie or solid core wire to each pipe and bend in the middle so the can is suspended from a point central point. Attach the swivel to said point or make an eyelet by twisting the wire and dangle from the thread/string. Attach the end of the string to something above the stove say a rafter in the garage and light it up! I find a Blow Torch works best but you can use whatever is available.

If you have any acetone or ethanol then you can add roughly 5% to 95% Water which forms an azeotrope and will reduce the boiling point to about 75 degrees celcius, which is good for two reasons. Firstly it takes less time to boil and will boil faster and secondly it will hurt less if you get splashed with some water from inside the can as the liquid will be cooler. Obviously wear relevant safety equipment including safety goggles and protective gloves.

I have almost finished the videos of it in action and when i have uploaded them ill post a link, they will probably be hosted on my website first though at:

Yes, your both right, the smaller you make your nossles the more pressure build up and the higher velocity of the exit vapours/gases. As Ke=(1/2*M)*V2 the Kinetic energy of the steam and hence its reactive force on the vessel on expulsion increases with the square of the exit velocity.

Also you could add a small amount of acetone to the water before you boil it, being careful to make sure it is mixed well. By a small amount i mean less than 10% although i cannot find the exact water acetone ratio right now. When you mix water and acetone together they form an "azeotrope" this is usefull because as the acetone boils/evaporates it takes molecules of water with it effectually lowering the boiling point of water from 100*C (pure water at 1bar atmospheric pressure) down to around 70-80*C (acetone-water azeotrope at 1bar atmospheric pressure). This means it will boil faster and produce more steam at 100*C than the pure water would.

More steam=more pressure=higher exit velocty vapours=more mass out per second. Going back to Ke=(1/2*M)*V2 if you increase the mass (flow rate ie mass out per unit time) the Kinetic Energy increases and since the same equation applies to the vessel and the mass is constantly decreasing as the azeotrope evaporates the velocity must increase.

The only other thing you could do would be to make the vessel lighter, more aerodynamic and reduce the rotational friction from the bearing. You could experiment with pipe lengths but lengthening increases torque action but decreases rpm, shortening increases rpm but decreases torque. (Torque is the rotational force applied to the vessel by the steam, too little torque and it wont have enough force to spin although this is unlikely).

In conclusion:@ Smallest Possible Holes/nossles.@ Add Less than 10% acetone to the water to lower the boiling point.@ experiment

Call that big? If the length of the the words you use is a measure of your intellect try this on for size: Antidisestablishmentarianism, I'm not a fan of medical terms so that's as long as I will go.

Joking aside, am I actually using particularly long words? I'm aware can be rather verbose at times but that's because I want to be clear. I use a few technical terms to be accurate but my intention isn't to bamboozle you. I don't think theres anything in there that the average person won't understand. Azeotrope may need a quick Google but I explained what it meant for those people who didn't know, I explained everything in case people didn't know the science, I even explained what torque was.

I'm an engineer, maybe I have a different perspective on what a big word or what simple is. I may do a "Building a... for dummies" series where the instructions are simplified. I could do it as a comedy series and write it in hill billy? Could be fun... Especially if it's to build something particularly precise, scientific and complex. I do enjoy irony.

Back on topicWould you get more power with more pipes attached? I wouldn't think so, since that would decrease the pressure inside because there would be more openings. More stability maybe?

If you want the smallest opening possible, could you make a hero's engine with only one pipe/arm/thingy? It would have to be balanced perfectly because of stability issues but I think it might be a bit more effective.

Ah, I see you have no problems with mediacal terms. Well done, that's one hell of a word and an interesting meaning.

Back on topicIf you want more power then boil something with a lower boiling point. adding more exhausts wouldn't help because what you gain in mass flow rate out of the engine, you lose in exit velocity. Increasing your torque but decreasing your pressure and top speed as the engine can only be propelled as fast as it's exhaust travels. One pipe may make it faster but it would probably require a solid shaft to spin on over a piece of string because of the stability issues you mentioned.

You would get the same effect by using smaller tubes. remember that it is the cross sectional area of the exhaust nozzle that effects the exit velocity so halfing the diameter doesn't half the area as the area is equal to pi multiplied by the square of the nozzle radius.

Thanks for the comment, its nice to get possetive feedback :D
Im not sure what you meant by 5ife? Im assuming it was a typo and you meant 5? I am pleased that someone has built one from my instructions, kind of makes it all worth while. Please can you take some photos/videos of your results and send them me? It would be a nice addition to the instructable: "other peoples results" and also i could put them on my website, obviously crediting you for your handywork of course.
LBO